What you find is not always what you fix—How other aspects than causes of accidents decide recommendations for remedial actions

In accident investigation, the ideal is often to follow the principle “what-you-find-is-what-you-fix”, an ideal reflecting that the investigation should be a rational process of first identifying causes, and then implement remedial actions to fix them. Previous research has however identified cognitive and political biases leading away from this ideal. Somewhat surprisingly, however, the same factors that often are highlighted in modern accident models are not perceived in a recursive manner to reflect how they influence the process of accident investigation in itself. Those factors are more extensive than the cognitive and political biases that are often highlighted in theory. Our purpose in this study was to reveal constraints affecting accident investigation practices that lead the investigation towards or away from the ideal of “what-you-find-is-what-you-fix”. We conducted a qualitative interview study with 22 accident investigators from different domains in Sweden. We found a wide range of factors that led investigations away from the ideal, most which more resembled factors involved in organizational accidents, rather than reflecting flawed thinking. One particular limitation of investigation was that many investigations stop the analysis at the level of “preventable causes”, the level where remedies that were currently practical to implement could be found. This could potentially limit the usefulness of using investigations to get a view on the “big picture” of causes of accidents as a basis for further remedial actions.     

A risk informed defense-in-depth framework for existing and advanced reactors

The philosophy known as ‘defense-in-depth’ has been used extensively in nuclear reactor safety evaluations and in justifying regulatory decisions. An evolving number of definitions of this philosophy have been proposed, primarily from a regulatory perspective. The purpose of this paper is to review the current definitions of defense-in-depth and to offer solutions to the technical issues identified from this review. A more general definition of defense-in-depth is proposed that can be used for any reactor concept. The proposed definition includes an explicit consideration of how the inherent characteristics of the reactor set the foundation for the safety case, an examination of how design features of a reactor employ the strategies of accident prevention and mitigation, and how to quantify the importance of design features responsible for prevention and mitigation. Application of this approach is demonstrated with use of examples for pressurized water reactors and modular high-temperature gas-cooled reactors.     

An analysis of the causes of freshwater immersion accidents involving children

An analysis is presented of the aetiological factors responsible for 111 consecutive childhood freshwater immersion accidents. The study comprises data from 56 survivors and 55 fatal cases in the Brisbane Drowning Study, being a total population five year analysis. A total of 16 separate aetiological factors have been identified. Quantitative scores for the relative importance of each of these have been calculated. Lack of parental supervision (78%), absent or inadequate safety barriers surrounding water hazards (63%) and an identifiable parental “vulnerable period” (44%) were the three most common factors. Most drowning accidents were due to multiple coincident causes; in only 16 cases (14%) could the accident be attributed to a single cause. Swimming pool accidents had a median of four separate but coincident causal factors compared with a median of two for those occurring in bathtubs, rivers and creeks. Causes have been classified according to three groups—environmental factors, parental factors, and factors relating to the child himself; quantitative scores for each of these causal groups, by immersion site, are presented. The significance of this work in the context of preventive strategems is discussed.     

Farm safety attitudes and accident involvement

Many safety educators firmly believe that good safety attitudes are a must if people are to avoid accidents in the workplace and elsewhere. This idea has evolved mainly from the industrial safety movement and has been adopted in most fields of safety. However, this fundamental adage has never been tested in agriculture. A random sample of Pennsylvania farmers were asked their attitudes toward nationally recognized farm safety concepts. The Semantic Differential Attitude Test was the instrument used to collect the data. Four hundred and ninety-three respondents indicated they have about the same attitudes toward farm safety concepts regardless of their accident involvement and regardless of other variables studied. The results of this study suggest that the apparent high priority given to safety attitude development as a primary means of accident prevention should be re-examined.     

The dark side of stimulus control--associations between contradictory stimulus configurations and pedestrians' and cyclists' illegal street crossing behavior

Since illegal pedestrian behavior represents a major source of accidents, research investigating possible reasons and risk factors for crossing against the lights is pivotal for enhancing safety in traffic. The present approach regards behavior at signalized intersections as a result of multiple stimulus discrimination. Hence, it is expected that at crossings divided by a median refuge the excitatory potential of a “consecutive green light” or “oncoming pedestrians” (S+*) attenuates the inhibition of crossing behavior induced by the relevant red light (S−). Standardized observations at critical intersections in Braunschweig, Germany, were conducted to investigate these hypotheses. Comparing outside traffic participants’ behavior in the presence of different stimulus configurations identified the assumed S+* as substantial risk factors for illegal crossings. Moreover, the presented model of stimulus control integrates past risk factor research and may help develop future prevention measures.     

A system of safety management practices and worker engagement for reducing and preventing accidents: An empirical and theoretical investigation

Objective

The overall research objective was to theoretically and empirically develop the ideas around a system of safety management practices (ten practices were elaborated), to test their relationship with objective safety statistics (such as accident rates), and to explore how these practices work to achieve positive safety results (accident prevention) through worker engagement.

Method

Data were collected using safety manager, supervisor and employee surveys designed to assess and link safety management system practices, employee perceptions resulting from existing practices, and safety performance outcomes.

Results

Results indicate the following: there is a significant negative relationship between the presence of ten individual safety management practices, as well as the composite of these practices, with accident rates; there is a significant negative relationship between the level of safety-focused worker emotional and cognitive engagement with accident rates; safety management systems and worker engagement levels can be used individually to predict accident rates; safety management systems can be used to predict worker engagement levels; and worker engagement levels act as mediators between the safety management system and safety performance outcomes (such as accident rates).

Implications

Even though the presence of safety management system practices is linked with incident reduction and may represent a necessary first-step in accident prevention, safety performance may also depend on mediation by safety-focused cognitive and emotional engagement by workers. Thus, when organizations invest in a safety management system approach to reducing/preventing accidents and improving safety performance, they should also be concerned about winning over the minds and hearts of their workers through human performance-based safety management systems designed to promote and enhance worker engagement.     

The special severity of occupational accidents in the afternoon: "the lunch effect"

The severity of occupational accidents suffered by construction workers at different hours of the day is analyzed in this study. It may be seen that the interval of time between 13:00 and 17:00 has incomprehensibly high rates of severe and fatal accidents in comparison with any other. We associate this higher accident rate with what we have termed the “lunch effect”. We studied 10,239,303 labor accidents in Spain over the period 1990–2002. The relationships between potential risk factors for occupational accidents around lunch in Spain, especially alcohol consumption are studied, using two methods: analysis of national archival data of 2,155,954 occupational accidents suffered by workers in the construction sector over the period 1990–2002 and a survey study. This study also seeks to contribute the opinions of the workers themselves regarding the causes that might explain this situation.     

Exposure and experience are a confounded nuisance in research on driver behaviour

Road accidents are usually the outcome of multicausal interface problems. Statistical controls therefore need to be equally complex, if accident analyses are to produce understanding of causal factors and lead to correction of contributory errors in driver behaviour. Crude control of accident data for distance travelled, time of day, etc. may identify high-risk groups. However, such controls could produce misleading results from research on individual differences in liability to error, because driving is basically self-paced and purposeful. Certain individuals will thus exhibit characteristically raised levels of risk exposure within the driving task, often as a result of pressures extrinsic to the traffic system. If the errors made by these individuals are to be identified, accident data must be corrected for such self-induced risk exposure, instead of this factor merely being used to “explain” accidents. This need seems most acute in experimental studies, where self-imposed demands and purposes of driving change over time and effects of exposure and experience are thus statistically confounded in accident data. However, control for self-induced risk exposure also seems important in studies of professional drivers' accidents and its neglect calls into question one of the basic assumptions of the “induced exposure” method of interpreting accident data.     

一起爆破飞石事故的事故树分析

在诸多露天采场爆破事故中,飞石事故占很大的比率,对矿区的安全生产构成了严重威胁.针对一起飞石事故案例,利用系统安全分析中的事故树分析方法,通过最小割集和最小径集的求取,寻找事故发生的原因,提出爆破飞石事故的预防途径和控制措施,从而有针对性地采取安全对策,以减少事故的发生.     

Age-related safety in professional heavy vehicle drivers: A literature review

With Australia facing a looming shortage of heavy vehicle drivers the question is raised as to whether it is desirable or prudent to encourage older professional heavy vehicle drivers to remain in the transport sector for longer, particularly those of heavy vehicles or recruit drivers of a younger age.

Aim

To review age-related safety and identify other factors that contribute to accidents experienced by heavy vehicle drivers.

Methods

A search was conducted of national and international peer-reviewed literature in the following databases: MedLine, Embase, Cinahl, PsychInfo and the Canadian Centre for Occupational Health & Safety. A manual search was performed to obtain relevant articles within selected journals.

Results

A limited number of studies reported age-specific accident rates for heavy vehicles for the spectrum of driver age that included drivers younger than 27 years and those over 60 years of age. Heavy vehicle drivers younger than 27 years of age demonstrated higher rates of accident/fatality involvement which decline and plateau until the age of 63 years where increased rates were again observed. Other contributing factors to heavy vehicle accidents include: long hours and subsequent sleepiness and fatigue, employer safety culture, vehicle configuration particularly multiple trailers, urbanisation and road classification.

Conclusions

Drivers of heavy vehicles are over-involved until age 27 years however a characteristic ‘U’ shaped curve indicates a higher risk of accident involvement for both younger and older drivers. More detailed analyses of “at-fault” involvement and inability to avert an accident and other factors that contribute to accidents across the ages of heavy vehicle drivers may give further clarification to the degree of safety of both younger and older commercial heavy vehicle drivers.     

The non-linearity of risk and the promotion of environmentally sustainable transport

Several studies show that the risks of injury to pedestrians and cyclists are highly non-linear. This means that the more pedestrians or cyclists there are, the lower is the risk faced by each pedestrian or cyclist. On the other hand, the more motor vehicles there are, the higher becomes the risk faced by each pedestrian or cyclist. The relationships found in previous studies suggest that if very large transfers of trips from motor vehicles to walking or cycling take place, the total number of accidents may be reduced. The “safety in numbers” effect for pedestrians and cyclists would then combine favourably with the effect of a lower number of motor vehicles to produce a lower total number of accidents. This paper explores if such an effect is possible, relying on the findings of studies that show the non-linearity of injury risks for pedestrians and cyclists. It is found that for very large transfers of trips from motor vehicles to walking or cycling, a reduction of the total number of accidents is indeed possible. This shows that the high injury rate for pedestrians and cyclists in the current transport system does not necessarily imply that encouraging walking or cycling rather than driving will lead to more accidents.     

Strategies for improving safety performance in construction firms

Over the years many prevention management practices have been implemented to prevent and mitigate accidents at the construction site. However, there is little evidence of the effectiveness of individual or combined practices used by companies to manage occupational health and safety issues. The authors selected a sample of 1180 construction firms and 221 individual practices applied in these companies to analyze their effectiveness reducing injury rates over a period of four years in Chile. Different methods were used to study this massive database including: visual analyses of graphical information, statistical analyses and classification techniques. Results showed that practices related to safety incentives and rewards are the most effective from the accident rate viewpoint, even though they are seldom used by companies; on the other hand, practices related to accidents and incidents investigation had a slight negative impact on the accident rate because they are frequently used as a reactive measure. In general, the higher the percentage of prevention practices implemented in a strategy, the lower the accident rate. However, the analysis of the combined effect of prevention practices indicated that the choice of the right combination of practices was more important than just the number of practices implemented.     

Jerky driving--An indicator of accident proneness?

This study uses continuously logged driving data from 166 private cars to derive the level of jerks caused by the drivers during everyday driving. The number of critical jerks found in the data is analysed and compared with the self-reported accident involvement of the drivers. The results show that the expected number of accidents for a driver increases with the number of critical jerks caused by the driver. Jerk analyses make it possible to identify safety critical driving behaviour or “accident prone” drivers. They also facilitate the development of safety measures such as active safety systems or advanced driver assistance systems, ADAS, which could be adapted for specific groups of drivers or specific risky driving behaviour.     

Too many or too few unintentional firearm deaths in official U.S. mortality data?

We examined the accuracy of data on unintentional firearm fatalities in the United States. We began with data from the National Violent Death Reporting System (NVDRS) and examined every firearm death reported as an accident by any NVDRS data source – the NVDRS abstracter, the State Vital Statistics Registry (i.e., the ICD-10 Underlying Cause of Death code and manner of death from the death certificate), the medical examiner or coroner report, and the police Supplementary Homicide Report. After carefully reading the information from all sources, we then classified each case as either unintentional or intentional using NVDRS definitions.Comparing our classification with that of the NVDRS abstracter, we conclude that NVDRS data accurately report unintentional firearm deaths (sensitivity 98%; positive predictive value [PPV] 99%). We then compared our classification with that of the State Vital Statistics Registry based on the ICD-10 Underlying Cause of Death code and found great inaccuracy (sensitivity 62%; PPV 58%). Thirty-eight percent of true cases were missed and 42% of reported cases were false positives. As has been previously reported in the literature, over half of unintentional shootings that were inflicted by another person were classified as homicides, not accidents. This is a particular problem for the data on young victims. What was unexpected, however, was the opposite problem: we found many unambiguous suicides and homicides that were reported as accidents. We believe this is due to the ICD-10 coding practice of assigning injury deaths to the “accident” category when manner of death is “pending” or left blank.Finally, at the state-level, we compared our overall results for each state and year with the official National Vital Statistics System count (reported on CDC's WONDER website). We found evidence of even greater over-reporting of unintentional firearm deaths there.In answer to the question, “Are there too many or too few unintentional firearm deaths in official mortality data?” the best answer is, “Both.” Many true accidents are missed, while many suicides and homicides are mistakenly reported as accidents. By contrast, the NVDRS applies a case definition for unintentional firearm deaths with consistency and accuracy.     

Child pedestrian's exposure,accidents and behavior†

Empirical data on children's exposure, accidents and behavior are a necessary prerequisite for the selection of the most important educational objectives, as specified in a concrete form by a more theoretical “behavior requirements analysis”. In this report an attempt is made to summarize the most important empirical findings in this area within the framework of a pedestrian task analysis developed earlier. The report starts with the presentation of a conceptual framework relating the concepts exposure, behavior, conflicts and accidents. The last chapter mentions several research needs which are relevant for the identification and selection of educational objectives and for the evaluation of educational and environmental countermeasures.     

Incorporating organizational factors into Probabilistic Risk Assessment (PRA) of complex socio-technical systems: A hybrid technique formalization

This paper is a result of a research with the primary purpose of extending Probabilistic Risk Assessment (PRA) modeling frameworks to include the effects of organizational factors as the deeper, more fundamental causes of accidents and incidents. There have been significant improvements in the sophistication of quantitative methods of safety and risk assessment, but the progress on techniques most suitable for organizational safety risk frameworks has been limited. The focus of this paper is on the choice of “representational schemes” and “techniques.” A methodology for selecting appropriate candidate techniques and their integration in the form of a “hybrid” approach is proposed. Then an example is given through an integration of System Dynamics (SD), Bayesian Belief Network (BBN), Event Sequence Diagram (ESD), and Fault Tree (FT) in order to demonstrate the feasibility and value of hybrid techniques. The proposed hybrid approach integrates deterministic and probabilistic modeling perspectives, and provides a flexible risk management tool for complex socio-technical systems. An application of the hybrid technique is provided in the aviation safety domain, focusing on airline maintenance systems. The example demonstrates how the hybrid method can be used to analyze the dynamic effects of organizational factors on system risk.     

Conceptualizing and communicating organizational risk dynamics in the thoroughness–efficiency space

Organizations that design and/or operate complex systems have to make trade-offs between multiple, interacting, and sometimes conflicting goals at both the individual and organizational levels. Identifying, communicating, and resolving the conflict or tension between multiple organizational goals is challenging. Furthermore, maintaining an appropriate level of safety in such complex environments is difficult for a number of reasons discussed in this paper. The objective of this paper is to propose a set of related concepts that can help conceptualize organizational risk and help managers to understand the implications of various performance and resource pressures and make appropriate trade-offs between efficiency and thoroughness that maintain system safety. The concepts here introduced include (1) the thoroughness–efficiency space for classifying organizational behavior, and the various resource/performance and regulatory pressures that can displace organizations from one quadrant to another within this space, (2) the thoroughness–efficiency barrier and safety threshold, and (3) the efficiency penalty that organizations should accept, and not trade against organizational thoroughness, in order to maintain safety. Unfortunately, many accidents share a conceptual sameness in the way they occur. That sameness can be related to the dynamics conceptualized in this paper and the violation of the safety threshold. This sameness is the sad story of the Bhopal accident, the Piper Alpha accident, and score of others. Finally, we highlight the importance of a positive safety culture as an essential complement to regulatory pressure in maintaining safety. We illustrate the “slippery slope of thoroughness” along which organizational behavior slides under the influence of performance pressure, and suggest that a positive safety culture can be conceived of as “pulling this slippery slope” up and preventing the violation of the safety threshold.     

Taxonomic analysis of Chinese power transmission and distribution industry accidents based on hazard components

Power transmission and distribution were critical components for the development of Chinese economy. As in all sectors of the economy it was important to reduce the accidents rate as low as possible. This research adapted accident taxonomic analysis to identify the main factors associated with accidents and then provided accident prevention countermeasures in the industry in China. Because of lack of systematic power transmission and distribution accident information in China, 324 power grid accidents from 1961 to 2008 were collected through a wide range of sources and classified according to hazard elements which were target and threat, hazard element and initiating mechanism respectively and then the initiating mechanisms were further classified by hazard types. Through taxon structures the direct and indirect factors were identified in the industry accidents and strategies of accident prevention were recommended based on them. The taxon structures also can be further developed to form tailored safety checklist for the front workers.     

煤矿综采面安全生产评价研究

[摘要]矿井事故高发区域是煤矿综采工作面,煤矿环境的特殊在很大程度上增加了确保安全生产的难度系数,矿井生产具有其他行业所不具有的特殊性、复杂性以及多变性,其中发生率较高的矿井事故类型有透水、煤炭自燃、瓦斯或煤尘爆炸以及职业病等。本文首先介绍了综采工作面常见事故类型,其次阐述了构建煤矿综采面安全生产评价指标体系应遵循的原则,最后对确定综采工作面安全生产评价指标权值加以探讨。